"Heart of Stone" is the fourteenth episode of the third season of the American science fiction television series Star Trek: Deep Space Nine, and originally aired on February 6, 1995 in broadcast syndication. The story was written by Ira Steven Behr and Robert Hewitt Wolfe, while the episode was directed by Alexander Singer and the score was created by David Bell. Set in the 24th century, the series follows the adventures on Deep Space Nine, a space station located near a stable wormhole between the Alpha and Gamma quadrants of the Galaxy; the Gamma Quadrant is home to an empire known as the Dominion, ruled by the shape-shifting Changelings. In this episode, Deep Space Nine's security chief Odo (René Auberjonois), a rogue Changeling who has rejected the Dominion, and Major Kira Nerys (Nana Visitor) are trapped together on a small moon, forcing Odo to admit he is in love with Kira; meanwhile, on the station, the Ferengi teenager Nog (Aron Eisenberg) tries to get Commander Benjamin Sisko's (Avery Brooks) support for his application to Starfleet Academy. The character arcs launched in this episode, of Nog joining Starfleet and Odo dealing with his feelings for Kira, would be central to the two characters for the remainder of the series. The episode was the fourth most watched episode of the third season, with 8.3 million viewers, and received a mixed critical response. Plot On board a runabout, Odo and Kira are in pursuit of a member of the terrorist group known as the Maquis. They follow the Maquis vessel to a small moon. Landing, they find the vessel is empty, and split up to search for the pilot. After a short while, Odo returns to find Kira with her foot caught in an expanding crystal mass that Odo is unable to remove. As Kira is slowly being covered by the crystal, dangerous seismic tremors increase in the surrounding rock; Kira insists that Odo abandon her and flee to safety. He attempts to free her using an ultrasonic generator, and tells her about his past as they wait for the crystal to shatter. When the generator fails to work, and Kira is nearly engulfed in the crystal, Odo confesses his love for Kira. To his surprise, she says she is in love with him too. Suspicious of Kira's response, Odo points a phaser at her, demanding to know who she really is. Kira